1. Field of the Invention
The present invention relates to processing cells of automatic machining system and an automatic honing system, and more particularly, for example, to automatic machining techniques such as automatic honing executed on sub-machined work sequentially carried at predetermined intervals along a work carrying passage for sequentially continuous machining by means of a boring machine and a honing machine disposed halfway in the work carrying passage.
2. Description of the Related Art
For example, honing is available as one of machining methods for accurately finishing work bore surfaces. In honing, a honing tool and work are placed in a state of relatively floating, then the honing tool is given rotational and reciprocal motion, and the work bore surfaces are accurately finished while expanding the grindstone of the honing tool by means of a wedge or cone.
Recently, as a device for efficiently honing work bore surfaces as mass-produced products such as the bore surfaces of automobile parts, there has been developed an automatic honing system which comprises a plurality of honing machines arranged in a row for executing sequentially continuous honing on work carried at predetermined intervals.
An automatic honing machine of this type is, for example, as shown in FIG. 36, is configured in that a work carrying passage a is disposed in loop form, and in the work carrying passage a are arranged work loading section b, work machining section c, and work unloading section d.
And, at the work loading section b, work W lined up and fed by the work feeder e such as a parts feeder is fitted on honing jig g being in a standby condition at disposing position P of the work carrying passage a by means of robot unit f. The honing jig g with work W fitted and held thereon is brought by loader h to the position of under-bore detector i, and the under-bore diameter of the machining hole of work W is detected by the under-bore detector i.
Subsequently, at the work machining section c, the honing jig g with work W held thereon is transferred in tact fashion by transfer unit j to rough honing machine k --> first measuring device 1 --> middle honing machine m --> second measuring device n --> finish honing machine o --> third measuring device p, and is also positioned at the position of each unit, and thereby, specified honing steps are sequentially automatically executed.
In this way, work W with honing completed at the work machining section c is cleaned by brush unit q, and thereafter, the work is delivered to the disposing position P by means of unloading unit r, feedback unit s and push-in unit t of the work unloading section d, and again, the work is sorted by the robot unit f of the work loading unit b in accordance with the result of measurement of the third measuring device p, and thereby, non-defectives are delivered to non-defective unloading chute u, and defectives are unloaded into NG chute v.
This automatic honing system is designed as an exclusive machine specialized according to the shape and size of specific work W to be machined and its machining conditions, and all components a, b, c, d are securely integrally installed on a large frame (not shown) and are driven by control unit x which controls the whole system all together.
However, such a system configuration designed as an exclusive machine for specific work W involves various problems mentioned in the following.
(1) The number of honing steps is determined in accordance with the under-bore shape accuracy, cutting margin and required shape accuracy of work W, but the under-bore shape accuracy and cutting margin at the stage of trial are unstable.
Accordingly, in such a configuration that all components a, b, c, d are securely integrally installed on a large frame and that the whole system is controlled all together by one control unit x, the number of steps cannot be determined until coming to the final stage.
(2) For the same reasons, in case the under-bore accuracy of work W is changed or the machining accuracy required for work W is changed, the number of steps cannot be determined.
(3) Also, for the same reasons, when the prediction of the production quantity of work W is difficult, it is accompanied by difficulty in making the decision on investment.
(4) Because of being designed as an exclusive machine for specific work W, when there is no need of production of the specific work W, it is necessary for machining other work different in shape, size and machining conditions to remodel the mechanical configuration of the whole system. Also, in case such remodeling is impossible, the system itself has to be discarded, resulting in increase of the installation cost.
(5) Since the system structure of each component a, b, c, d is configured as one system as a whole, the common system for each component unit such as a hydraulic unit being a driving source for each component unit and a cutting oil tank used in machining operation is to be relatively large in size and separately installed, and as a result, the whole system becomes complicated and larger in size, causing the installation cost to be increased.
Most of these problems are common to automatic machining systems including the automatic honing system which executes sequentially continuous machining of work such as various mechanical parts as mass-produced products by means of a plurality of machine tools arranged in a row.